Preparation And Photocatalytic Properties Of Polyimide/Metal Oxides Composite Films

Polyimide(PI)was used as the carrier and PI/mental oxide composite films was prepared through an ion exchange process and in situ deposition process.The preparation conditions influencing photocatalysis were studied.Furthermore,the composite films were modified by compound semiconductor and the optimal doping contents of metal ions on the composite films were studied.The morphology and structure of samples were characterized by different methods such as Scanning Electron Microscope(SEM),X-ray Diffraction(XRD),and Attenuated Total Reflection Flourier Transformed Infrared Spectroscopy(ATR-FTIR),and the degradation rate of Methylene Blue trihydrate(MB)were used to evaluated the photocatalytic activity of the samples.(1)PI/Ce2O3-CuO composite films were prepared by the surface modification and ion exchange process.The results showed that the composite films which were calcined 4h at 350?have a best photocatalytic activity,the degradation rate of MB is 92.7%.Degradation rate of MB by recycled composite films is 83.7%.(2)PI/Ce2O3-SnO2 composite films were prepared by the surface modification and ion exchange process to improve photocatalytic activity.The results showed that the composite films which were calcined 4h at 330? and Ce3+ content is 30%have a best photocatalytic activity,the degradation rate of MB is 94.5%.The particle size of catalyst is about 15nm.(3)PI/In2O3-SnO2 composite films were prepared by the in situ deposition process.The results showed that the composite films which were calcined at 390? have a best photocatalytic activity,the degradation rate of MB is 96.8%.(4)PI/In2O3-Fe2O3 composite films were prepared by the in situ deposition process.The results showed that the photocatalytic activity of composite films is the best when the content of In and Fe is 5:5,the degradation rate of MB is 94.2%.Crystal diffraction peak appeared in the composite film XRD pattern and the crystal particle size is about 13nm.